Performance improvement of the CP-V loader through use of the ADAM hardware monitor
John P Collins · ACM SIGMETRICS Performance Evaluation Review · 1976
The ADAM hardware monitor can be used to localize and identify several types of performance-impairing behavior in user programs. This paper presents a case study for such an improvement carried out on the CP-V overlay loader. Through measurement of the execution behavior and the subsequent analysis of the resulting data, problems of three basic types were identified: 1. The presence of inefficiently coded routines in areas of high execution intensity; 2. The use of overly general routines along heavily-used program paths; and 3. The use of inefficient algorithms for processing the large amounts of data with which the loader deals. The subsequent redesign and recoding of the problem areas have resulted in a significant performance improvement: the time required to load a program has been reduced by a factor of between two and ten, dependent upon the nature of the program and the loader options specified.